Apparatus for controlled burning of liquefied petroleum gas



Jan. 11, 1966 APPARATUS FOR CONTROLLED BURNING OF LIQUEFIED PETROLEUMGAS Filed OCT,- 29, 1962 3 Sheets-Sheet 1 coN-moL T F 1* i 30 r46 1120aVALVE l 20b 44 w 52 T50 r 42 I I REG. REG. ACTUATE I l 445 8 I r VALVE I-20: I 1 L L m J l I [/0 (56 obTLET x 2 VALVE ii: MASTER BURNER INVENTORGEORGE J. HEBERLE/N ATTORNEYS Jan. 11, 1966 G. J. HEBERLEIN 3,228,447

APPARATUS FOR CONTROLLED BURNING OF LIQUEFIED PETROLEUM GAS Filed on.29, 1962 s Sheets-Sheet 2 INVENTOR BY ism George J Haber/em mm, n NR x lv Q b f bi bi .QN Ni I ATTORNEYS Jan. 11, 1966 e. .1. HEBERLEIN3,223,447

APPARATUS FOR CONTROLLED BURNING OF LIQUEFIED PETROLEUM GAS Filed 061.29, 1962 5 Sheets-Sheet 3 Gearge J. Hebe/lain lNVE NTO R ATTO R N EYSUnited States Patent M 3,228,447 APPARATUS FUR CONTROLLED BURNING 6FLIQUEFIED PETROLEUM GAS George J. Heberlein, R0. Box 518, Ault, Colo.Filed Oct. 29, 1962, Ser. No. 233,617 13 Claims. (Cl. 158-128) Thisinvention relates generally to methods of, and apparatus for, burningL.P.G. The designation L.G.P. is used conventionally in the trade andart, as well as in the instant specification and claims to designateliquefied petroleum gas.

As well known, L.P.G. normally exists in both a liquid state and a vaporstate. In fact, when L.P.G. is enclosed within a tank, or other suitablecontainer, the same possesses the inherent ability to generate its ownvapor under pressure within the tank or container, provided the tank orcontainer and contents thereof are maintained at ambient temperaturessuch as normally existent in the atmosphere. Thus, L.P.G. is customarilycommercially available in a strong-wall tank having a top valve outlet.As stored in such tank, the L.P.G. comprises a liquid body filling thelower portion of the tank at least, and a vapor body disposed above theliquid body within the tank, and conventionally communicating with thevalve outlet of the tank.

Possibly the most common use of L.P.G. is in communities where utilitygas lines are not available, and stoves are operated from L.P.G. (eg.propane or butane) tanks. In such instances, the tanks are disposedexteriorly of the building and a suitable line is run within thebuilding to the stove. The stove burner is coupled with the vapor bodyof L.P.G. within the tank, which by virtue of the inherent properties ofthe L.P.G. is under pressure. The L.P.G. vapor delivered to the stove isburned at a sufficiently slow rate that the L.P.G. itself generatessufficient vapor continuously to replace that which is used by thestove, thus maintaining adequate pressure within the tank for automaticsupply therefrom to the stove burner.

While the foregoing conventional use, and similar conventional uses,permit the burning of the L.P.G. vapor itself, and the replacement ofthe vapor body and pressure within the tank through the inherentproperties of the liquid L.P.G. within the tank, where a substantialquantity of heat is to be generated, the foregoing arrangement does notfunction properly. Specifically, where substantial heat is to beproduced, the requirement for fuel can result in an attempt to drawL.P.G. vapor from the tank at a faster rate than the rate at which thevapor can be replaced by the inherent vaporization of the L.P.G. withinthe tank. Thus, where a substantial quantity of vapor is to be burned,either a sufiicient and substantial number of L.P.G. tanks are required,or the pressure Within the tank or tanks being used becomessubstantially reduced so that the supply of L.P.G. vapor cannot bemaintained at a proper rate. Moreover, where an attempt is made to drawa substantial quantity of vapor from a tank at a rapid rate, the tanktends to freeze. In this latter regard, it will be remembered that thereis a reduction of pressure Within the tank first if the draw thereonexceeds the rate at which vaporization occurs therein and secondly,there is substantial heat taken away from the tank in vaporizing theliquid within the tank to produce the vapor within the tank. Thiscombination of factors results in the freezing, and also contributes tothe reduction in B.t.u. output of the burner system.

In view of the above conditions, it is recognized that the vaporexistent in an L.P.G. tank cannot be tapped as a suitable source forproducing a substantial heat output. Accordingly, it has previously beensuggested that the L.P.G. in liquid form existent within the tank beused as a fuel for any burner wherein a substantial heat is to be3,228,447 Patented Jan. 11, 1966 produced, and that the vapor existentwithin the tank be used merely for purposes of maintaining the liquidwithin the tank under suitable pressure. To achieve this purpose, atube, commonly known as a dip tube, is inserted within the L.P.G. tankin communication with the lower portion thereof containing L.P.G. in aliquid state. The pressure which is built up by the L.P.G. vapor withinthe tank and above the liquid body forces the liquid body through thedip tube and into a suitable supply line. The liquid which is enteringthe line is then vaporized, in some suitable fashion, and as vaporized,burned to produce the desired heat within the burner or by the burner.The drain of liquid from the L.P.G. tank in this instance, even forsubstantial burning, is suificiently small that the pressure of L.P.G.vapor within the tank is maintained within proper limits. (Acomparatively small quantity of liquid is needed to produce asubstantial quantity of burnable vapor.) Thus, the liquid body withinthe tank is constantly maintained under suitable pressure, and the feedof liquid to the burner is maintained by the pressure inherentlyavailable in the tank due to the continuous vaporization of the liquidL.P.G. within the tank as liquid L.P.G. is drained or drawn therefrom.While the above basic operating techniques or method have previouslybeen suggested, there are many instances where it is necessary ordesirable to produce a substantial quantity of heat with an L.P.G.burner system, and-yet where it is necessary to control the quantity ofheat produced whereby a particular characteristic of a given substanceheated by the system, such as the temperature, pres sure or levelthereof, can be maintained within a prescribed range. For example, incertain road construction operations, it is desirable to maintain an oilused in the formation of an asphalt surface within a predeterminedtemperature range. Substantial heat is required for this purpose, and atthe same time, in many instances, oft-on type control is necessary.Another instance when such a system may be used is encountered in an oilfield where one desires to obtain, through conventional methods, aseparation of oil and water, for example. These two particular types ofoperations wherein a system such as described in this paragraph may beused are but exemplary of various types of operations, and are set forthmerely for purposes of explaining exemplary utility of the instantinvention.

As suggested above, in order to burn the liquid body of L.P.G. existentwithin a conventional L.P.G. tank, it is necessary to vaporize the samein some manner. This either requires the use of a rather complexvaporizing system, the use of a spray-type nozzle or orifice which caneasily become clogged, or the use of a special burner which I havepreviously developed and which is described in my prior United StatesPatent No. 2,851,096. The use of complex vaporizing systems is, ofcourse, undesirable, as is the use of cloggable nozzles, and accordinglya burner such as described in my aforesaid prior patent is incorporatedin any burner system where L.P.G. liquid is to be burned. Such a burneris simple in construction, and operates to vaporize liquid L.P.G.therein Without the use of a cloggable nozzle or small orifice, butstill such a burner is more expensive than a simple outlet such as isneeded for a pilot for the burner system. Moreover, for purposes ofproviding a pilot for the burner system, it is not necessary to generateany substantial quantity of heat since the pilot merely serves tomaintain combustion so that there is automatic ignition of the primaryburner or main or master burner system.

A primary object of the present invention is to provide a method of, andapparatus for, burning L.P.G. which overcomes the above disadvantages,and utilizes the inherent properties of the L.P.G. to the bestadvantage. Specifically, a primary aspect of the present invention liesin the discovery that it is preferable to operate a burner system withL.P.G. by utilizing the likuid body of L.P.G. within an L.P.G. tank forthe main burner thereof, and by utilizing the vapor body within anL.P.G. tank for the pilot burner system fuel supply. Consistent withthis aspect of the invention, a burner system having a pilot and a mainburner capable of producing substantial heat is operated by supplying tothe main burner liquid fuel from the L.P.G. tank and by supplying to thepilot burner, which is of very small capacity, vapor fuel from theL.P.G. tank. This eliminates the above discussed problems which resultfrom supplying vapor fuel from the L.P.G. tank to the main burner, andalso eliminates the need for providing a vaporizing system and/ or aspecial burner as the pilot.

Aside from the foregoing basic aspects: of the invention, the same isalso concerned with the provision of a control system which can be usedin accordance with the method hereof to control the operation of theburner system. Specifically, the invention is concerned with providing acontrol system which is not in any way dependent on an outside suorce ofpower, which operates automatically to shut-off the entire system in theevent of pilot failure, and which in addition automatically controls theheat supply to a body of material to maintain a predeterminedcharacteristic thereof (e.g., temperature, pressure or level), within apredetermined temperature range by the burner system. Consistent withthis latter phase of the invention, the invention has as primaryobjects: (a) the provision of a method for controlling the feed ofL.P.G. from a conventional L.P.G. tank to an L.P.G. burner system, whichmethod takes advantage of the inherent properties of the L.P.G. toachieve most efiicient burning, which method utilizes L.P.G. vapor foreffective system control, and which method utilizes power generated byand through operation of the system to power controllable components;(b) to provide an apparatus for carrying out such method, whichapparatus is simple in construction, trouble free in operation, andformed substantially entirely from available components, and/or suitablyconstructed auxiliary components; and (c) to provide such an apparatuswhich can be independently provided on a moving vehicle, or transportedfrom place to place, for use independently of outside power and withcommercially available L.P.G. tanks.

A still further aspect of the present invention lies in the provision ofa pressure responsive activating device which is adapted to control asupply valve assembly, and yet maintain an efiectively sealed line inuse. More specifically, in this regard, it isa primary object of thepresent invention to provide a pressure responsive activating devicewhich can be easily constructed and used in a control system providedhereby which is operated in accordance with the methods hereof.

The invention lies in the methods of operation, apparatus combinations,and construction and arrangement of components, as will be more fullyappreciated when consideration is given to the following detaileddescription of the invention. Moreover, objects other than those setforth above, and advantages other than those specifically recited in thepreceding discussion, will become apparent after reading suchdescription.

The description refers to the annexed drawings, presenting preferred andillustrative embodiments of the invention, and wherein:

FIGURE 1 is a schematic diagram, in box form, showing a system whichoperates in accordance with the methods hereof;

FIGURE 2 is a schematic view of a slightly modified arrangement andcoupling between exemplary components provided in a control systemconstructed in accordance herewith;

FIGURE 3 is an exploded view of a pressure responsive activating deviceconstructed in accordance herewith;

FIGURE 4 is a plan view of the pressure responsive activating deviceshown in FIGURE 3; and

FIGURE 5 is a cross-sectional view of a pressure responsive activatingdevice as shown in FIGURE 3, when the same is in assembled condition.

Method of operation The methods provided by the instant invention arefor opera-ting a burner apparatus having, as shown in FIG- URE 1, amaster burner system 10 including a master burner fuel outlet andvaporizing means for converting liquid fuel fed to the burner systemfrom a liquid state to a vapor state, and a pilot burner system 12including a pilot fuel outlet ignitably associated with the masterburner fuel outlet. As explained more fully below, the particularconstruction of the master burner system and the particular constructionof the pilot burner system form no part of the instant invention, andany conventional systems can be used respectively in the boxesdesignated by the numerals 10 and 12 in FIGURE 1.

The burner apparatus, as suggested above, is to be operated with L.P.G.,and as conventional such L.P.G. is carried within a suitable tank suchas that schematically shown in FIGURE 1 and designated by the numeral14. The tank 14 is enclosed and contains L.P.G. in a liquid state in thelower portion 16 thereof and L.P.G. in a vapor state in the upperportion 18 thereof. The liquid L.P.G. in the lower portion 16 inherentlyvaporizes thus forming the vapor L.P.G. in the upper portion 18 of thetank 14, and the vapor continues to :be formed from the liquid untilequilibrium is reached. Naturally, as the tank 14 is obtained from acommercial establishment, the same is in equilibrium condition, andmoreover includes a suitable valve connection at the upper end 14'thereof.

Having now explained the burner system, and the source of fuel withwhich such system is operated in accordance herewith, attention can bedirected to the method steps used in the operation.

First, and very basically, the method hereof contemplates directingL.P.G. in a vapor state solely from the upper portion 18 of the tank 14to the pilot fuel outlet of the pilot burner system 12. The line 20shown in FIGURE 1 and including the respective sections 20a, 20b, and200 serves this purpose. Secondly, L.P.G. in a liquid state is directedsolely from the lower portion 16 of the tank 14 to the master burnersystem 10. The line 22 shown in FIGURE 1 serves this purpose, as it isconnected at one end with a suitable dip tube schematically shown inFIGURE 1 and designated by the numeral 24, and at its other end with themaster Iburner system 10 itself. Such master burner system includes avaporizer 26 which is preferably part of the master burner itself. Inthis regard, attention is again directed to my prior US. Patent No.2,851,096 which discloses a burner arrangement wherein liquid L.P.G. fedthereto is vaporized in coils extending circu-mferentially of the axialpath of the fuel outlet. Actually, in the burner system of my aforesaidprior patent, the vaporizing means and combustion chamber are combinedinto a unitary structure wherein the L.P.G. is vaporized in coilsdisposed about the vapor L.P.G. outlet thereof, and the coils in essencedefine the combustion chamber. The burner as disclosed in this patentcan well be used as the master burner in a method operated in accordanceherewith, however, it is to be understood that other forms of masterburners can be used including those having a separate vaporizing systemand those having a vaporizing orifice. In any event, consistent with themethod hereof,.and consistent with a generic description of differenttypes of burner systems which can be used in accordance herewith, theL.P.G. fed to the vaporizing means 26 of the master burner system 10 isconverted into a vapor state within the vaporizing means, and thendirected, as converted, from the vaporizing means 26'to the masterburner fuel outlet which is schematically shown in FIGURE 1 anddesignated by the numeral 28.

From the above, it will be apparent that vapor L.P.G. is fed from theupper portion 18 of the tank 14 to the pilot burner system, and thenburned thereadjacent. Similarly, the liquid L.P.G. which is fed from thelower portion 16 of the tank 14 is converted into a vapor in thevaporizing means 26, and then fed to the master burner fuel outlet 28where it is burned thereadjacent.

Utilizing the vapor L.P.G. from the upper portion 18 of the tank 14permits the use of a very simple pilot burner system, and since the drawon the vapor by such pilot system is substantially small, the pressureWithin the tank 14 can easily be maintained. At the same time, the useof the liquid L.P.G. from the lower portion of the tank 14 provides anadequate fuel supply for the master burner means or system It) so thatsubstantial heat can be generated thereby. The basic aspects of theinvention thus in and of themselves afford substantial advantage.Although the method is operative where only small quantities or" heatare to be produced, the same finds substantial advantage where thequantity of LPG. as converted and fed to the master burner fuel outletis substantially greater per given unit of time than the quantity ofLPG. fed to the pilot fuel outlet during a heating operation.

Aside from the basic aspects, but consistent therewith, the steps abovedescribed are carried out by controllling the quantities of L.P.G.directed from the tank to the pilot fuel outlet and from the tank to themaster burner system and specifically the vaporizing means thereof so asto maintain the pressure of LPG. in a vapor state within the tank and onthe LPG. in a liquid state within the tank at least substantiallyconstant while the other steps are performed. To this end, regulatorssuch as those schematically shown in FIGURE 1 and designatedrespectively by the numerals 3i? and 32 can be provided in a bypassbranch 4-4 of the supply line 20 and in the supply line 22,respectively.

The method hereof, as indicated in the introductory portion of thisspecification finds particular utility when the burner system isutilized for purposes of heating a given body requiring substantialheat, or for purposes of controlling a particular characteristic of agiven body (e.g. temperature, pressure or level) where substantial heatis required for the control. Since temperature sensing elements, levelsensing elements and pressure sensing elements are well known, and sincea desired type output can be obtained from a particular element,regardless of the characteristic sensed, the invention is describedbelow in connection with a temperature sensing operation. It is to beunderstood, however, that the methods and apparatus are applicable tosensing of various characteristics, and that while temperature sensingis important the sensing phase of the invention is not limited thereto.There is shown in FIG- URE l a tank 34 having a fluid body 36 therein inliquid form. The master burner system is shown as being disposed to heatthe fluid body 36. Now, in this example, the characteristic to be sensedis temperature and the method hereof contemplates sensing when thetemperature of the body 35 has reached at least one predetermined level,and then controlling the feed of LPG. to the master burner outlet inresponse to sensing of the predetermined temperature level. Thus, asuitable sensing means 38 is provided consistent with the method tosense the temperature of the liquid body at least within a predeterminedrange having at least general upper and lower limits. For example, letit be assumed that the body 36 is to be maintained at a temperature ofapproximately 300 F. The sensing means, in such instance, and consistentwith the method hereof, might well be capable of providing somechangeable characteristic, such as an output current, an outputpressure, or the like when the temperature sensed is approximately 310,and might well revert to the original characteristic when thetemperature of the body 36 is, for example, 290. Thus, there is a rangeof temperatures being sensed, and there are at least general upper andlower levels. The upper and lower levels may be closer together thanthose in this example, or they may be spread further apart, but normallyany sensing means which is utilized need only be sensitive approximatelyto temperature variations.

Bearing the foregoing in mind, and still further in conformity with themethods hereof, the feed of L.P.G. to the master burner system 10, orspecifically the vaporizing means 26 thereof would be stopped inresponse to sensing of the upper level within the predetermined rangesensed by the sensing means, and the feed of LPG. to the master burnersystem 10 would be started in response to sensing of the lower levelWithin the predetermined range of temperatures in question. In otherwords, the basic method contemplates sensing a characteristic of thebody being heated by the master burner system which characteristic isrelated to the heat transferred to the body by the burner system, andthen starting and stopping the feed of fuel to the master burner systemfrom the lower portion 16 of the tank 14 in accordance with thecharacteristic sensed.

To achieve the above described control, further method steps areprovided hereby. Specifically, in this latter regard, the inventioncontemplates enclosing a portion of the LPG. in a vapor state which isdirected from the upper portion 18 of the tank 14 in a storage areaseparate from but communicating with the upper portion of the tank. Thestorage area, in this instance, and as shown in FIGURE 1 includes anauxiliary line 40 having an activating device 42 coupled therein. Theauxiliary line 40 is connected to a parallel branch 44 in the supplyline 20, the parallel branch 44 including respective sections 44a, and441) which are joined at opposite ends with the section 201) of thesupply line 2t). The storage area may take other forms than thatdescribed immediately above, but the exemplary form described and shownin the drawing illustrates the operation of the method hereof.

With the supply area connected as described above, the enclosed portionof the L.P.G. within the storage area normally has a pressure at leastproportional to the pressure of LPG. vapor within the tank 1 3. Now, theinvention contemplates using the pressure of the L.P.G. in the storagearea to effect the stopping and starting of the feed of LPG. to themaster burner system 10. Consistent with this approach, the pressure ofthe L.P.G. in the storage area is at least substantially reduced inresponse to sensing of the upper level within the predetermined range oftemperatures being sensed by closing communication between the tank 14and the storage area, and permitting L.P.G. in the storage area to passtherefrom. Still further, the pressure is substantially increased in thestorage area in response to sensing of the lower level Within thepredetermined range of temperatures, by opening communication betweenthe tank 14 and the storage area. These steps are performed in theexemplary arrangement of FIGURE 1 by operating a valve such as thatdesignated by the numeral 46 with the sensing means 38 so that the valveshuts ofif communication to the auxiliary line 48 when the upper levelof temperature is sensed and so that the valve passes vapor to theauxiliary line 40 when the sensing means indicates that further heat isto be supplied by the master burner system. Naturally, the pressure isincreased in the storage area when the valve 46 is open, and asexplained in the following paragraph, the pressure automaticallydecreases in the storage area when the valve 46 closes.

Specifically, in this latter regard, and consistent with the methodhereof, L.P.G. in the storage area is permitted to pass therefromthrough the branch 44b of the line 44 when the valve 46 is closed. Toinsure the passage of LPG. from the storage area, and to direct the sameto the pilot burner system for use therein, so as to eliminate Waste ofgas, the method contemplates controlling the feed of L.P.G. from theupper portion of the tank to the pilot burner system 12 and controllingthe feed of L.P.G. permitted to pass from the storage area to the pilotfuel outlet thereof to provide a continuous substantially uniform feedof L.P.G. to the pilot fuel system, or specifically pilot fuel outletthereof and continuous burning of the fuel passing thereto. Thus,regulators such as those designated by the numerals 52 and 50 areincorporated respectively in the branch b directly, and bypass branch44b thereof. The regulator 50 and the regulator 52 close when the backpressure, i.e. pressure on the pilot burner system side thereof, exceedscertain values. Specifically, the regulator 52 will close to prevent theflow of vapor therethrough when the back pressure thereon reaches agiven value, and the regulator 50 will close to prevent the flow ofvapor therethrough when the back pressure thereon exceeds anothercertain value. The closing value for the regulator 50 is higher than theclosing value for the regulator 52, and thus when vapor is permitted toescape from the storage area the regulator 52 is so adjusted that theback pressure caused thereby results in closing thereof, whereas theregulator 50 remains open to permit the drain of vapor therefrom fromthe storage area.

Now, having described the detailed method steps contemplated hereby, itis important to again review the overall system operation. It will beremembered that at the outset of this description it was stated thatliquid L.P.G. is sent directly from the base portion or lower portion 16of the tank 14 through the line 22 to the master burner system 10.Similarly, vapor L.P.G. is sent from the upper portion 18 of the tank 14through the line 20, and sections 20a, 20b, and 200 thereof to the pilotburner system 12. In normal operation, however, due to the setting ofthe respective regulators 50 and 52, the vapor passes through the valve46 and line 44 forming the bypass portion of the section 20b of the line20. Still, it will be noted that the vapor L.P.G. passes from the upperportion 18 of the tank to the pilot burner system.

It will be further noted that during the above described operation, theauxiliary line serves to provide a connection between the actuatingdevice 42 therein and the line 44 so that the pressure of the vaporL.P.G. within the line 44 is applied to the actuating device 42. Thisactuating device, as shown, is coupled to a valve 56 in the line 22, asby a mechanical connection schematically designated by the numeral 58.When the pressure transmitted .to the actuating device 42 is suflicient,as during normal operation, the actuating device serves to maintain thevalve 56 open, thereby permitting the passage of liquid L.P.G. from thebase portions 16 of the tank 14 through the line 22 to the master burnersystem 10. However, when the pressure of the vapor L.P.G. transmitted ordirected to the actuating device 42 is not sufficient, the same causesclosing of the valve 56, and thereby stopping of the supply of liquidL.P.G. from the tank 14 to the master burner system 10.

Now, in review, it will be seen that when the sensing device 38 operatesthe valve 46, and the valve 46 closes, there is no longer pressuretransmitted through the auxiliary line 40 to the actuating device 42,and as a result the same cannot maintain the valve 56 open. Thus, thesupply of liquid L.P.G. through the line 22 to the master burner systemis stopped. Simultaneously, however, due to the incorporation of theregulators 50 and 52, the vapor L.P.G. in the storage area formed by theauxiliary line 40 and actuating device 42 is permitted to pass from thestorage area through the regulator 50 and to the pilot burner system 12for burning therein. After a substantial quantity, and in fact almostall of the vapor within the storage area has passed through theregulator 50, then the back pressure in the branch 200 of the line 20 isminimal, and the regulator 52 opens thereby permitting the vapor in theupper portion 18 of the tank 14 to pass through the section 20a of line20, the section 20b and the regulator 52 therein, and then the section20c of such line to the pilot system 12. Thus, the pilot system remainsin operation at all times. Of course, the sensing arrangement 38 issensitive to a particular characteristic of the liquid body 36 (e.g.,temperature, pressure or level) which is maintained by the master burnersystem 10, and accordingly it will be seen that the characteristic ofthe body 36 to be maintained serves, in accordance with the methodshereof, to control the supply of liquid L.P.G. to the master burnersystem, through the use of the vapor L.P.G. originally supplied from thetank 14, and specifically the upper portion 18 thereof.

For safety purposes, and for purposes of providing a system which iswholly independent of an external power source, the invention furthercontemplates utilizing a generator such as that designated by thenumeral 60 for producing an electrical current in response to heatgenerated by the pilot burner system. This generator might well comprisea millivolt thermo-couple arrangement. The same is coupled with thevalve 46, and with a shut-off valve 48 connected in the line 20,preferably between the output couplings therein of the regulators 50 and52. The valves 46 and 48 are supplied with power by the generator 60,and when the pilot burner unit is not operating, as is apparent, thereis no supply of electricity from the generator, and accordingly both thevalves 46 and 48 close thereby preventing any fiow of L.P.G., either invapor form or in liquid form from the tank 14 to either the pilot burnersystem or the master burner system.

Apparatus Whereas a complete system has been shown in FIG- URE l whichis constructed in accordance herewith, and which is adapted to carry outthe method steps hereof, FIGURE 2 presents in some detail an actualassembly of components and the coupling therebetween for a controlsystem provided hereby. In the arrangement of FIGURE 2, it is assumedthat the line 20 is coupled at the input or lefthand end thereof withthe upper portion of an L.P.G. tank, and that the line 22, or left endthereof as shown is coupled with the lower portion of an L.P.G. tank inthe same manner as such lines are coupled with the respective portionsof the tank in FIGURE 1. Moreover, it is assumed that the outputcouplings 10 and 12' of the respective lines 22 and 20 are connectedwith a master burner system and a pilot burner system respectively, asindicated in FIGURE 1.

Bearing the above factors in mind, attention can be directed to suitablecommercially available components which can be provided in therespective lines. Initially, each of the lines 20 and 22 preferably hasconnected therein a needle valve 78 and 30 respectively. Following theneedle valve, an L.P.G. filter, preferably of type No. 302 produced by Iand S Carburetor Co. of Dallas, Texas, is connected in each of thelines. The line 20 leads from the filter 74 connected therein to theinput coupling of the regulator 52 and also to the input of theregulator 30. The regulator 30 may well comprise a Rego regulator No.567, and the regulator 52 may well comprise a Rego regulator No. 2302A2.As shown in FIGURE 2, there is connected with the regulator 30 anadjustment handle 31 and a gauge 70 which handle and gauge cooperate inuse to permit establishment of a proper feed pressure within the bypassbranch 44a of the line 20.

From the output of the regulator 52, the line 20 feeds through a Tconnection 102 to a safety valve 48 which may well comprise a GeneralControls thermo-pilot valve No. MR2YA07. The output of the safetycontrol valve is connected with the coupling 12' leading to the pilotburner systems.

In the bypass branch of the line 20, and following the regulator 36, isa valve arrangement 46 which is electrically responsive. Moreover, thevalve 48 referred to above is similarly electrically responsive. Theoutput of the valve 46 feeds to a T connection 104, and from the Tconnection through the regulator 59, as well as to the auxiliary line40. The regulator 50, like the regulator 52 may well comprise a Regoregulator No. 2302A2. The regulators designated by the numerals 50 and52, as conventional, are diaphragm-type regulators incorporatingadjustable spring biasing means which permit the setting thereof inadvance for closure in response to predetermined back pressures. Asindicated in the preceding section of this specification, the regulator50 is initally adjusted so as to be responsive to a higher back pressurethan the regulator 52, and these back pressures are adjusted so as toachieve the method steps referred to. Since the adjustments areconventional, further description thereof appears unnecessary.

The auxiliary line 40 feeds to the pressure responsive activating devicewhich preferably takes the form of the device shown in FIGURES 3 through5. This device, as explained more fully below, produces a mechanicaldisplacement of a connecting rod therein in response to the existence ofpressure within the auxiliary line 49. Such displacement is used toactuate a valve 56, which may be of any conventional design, providedthe same is operative in response to a displacement of a connecting rodto open and close a line in which it is connected. Various valves whichperform a closing and opening operation upon a downward push or downwarddisplacement are available, and virtually any of such forms may beutilized in accordance with this invention as the valve 56, provided thesame is adapted to control the liquid L.P.G. flow.

The valve 56 is, as explained, coupled in the line 22 following thefilter 76 therein, and the output of the valve 56 feeds to a regulator32 and then therethrough to the coupling At the regulator 32, there ispreferably provided an adjustment handle 33 together with a pressuregauge 72 whereby the ultimate pressure of LPG. fed to the coupling 10may be suitably adjusted by an operator.

It will be noted that the valve 48, which is a safety valve, ispositioned on the output side of the regulator 50 in the embodiment ofFIGURE 2, but positioned between the regulators 50 and 52 in theembodiment of FIGURE 1. The reason for this variation, and the reasonwhy the embodiment of FIGURE 1 is preferred will be explained below.

Now, in FIGURE 2, it is assumed that a suitable thermocouple millivoltarrangement is coupled with the burner to produce an electrical currentin response to heat generated thereby, and that the line from thegenerator leads to a control box 100. Such line is designated in FIGURE2 by the numeral 60'.

The control box 100, as shown diagrammatically in FIGURE 2, includes atiltable mercury switch 110 mounted in a suitable bracket 112 and havingcontacts 114 and 116 at opposite ends thereof. The contacts 114 and 116cooperate with mercury 118 to pass current through the mercury switchwhen the switch is in the position shown in FIGURE 2, however, when theswitch is tilted, for example, counterclockwise, the mercury remains inengagement with the contact 116, but not with the contact 114, so thatno current can flow through the switch.

The sensing device 38 which includes a sensing probe 120 and a pressureline 122 is coupled with the control box 100, and governs the movementof a reciprocal lug 124 within the control box. The lug 124 isengageable with the bulb of the mercury switch 111) to cause tiltingthereof against the action of a compression spring 128. When the probe120 senses a given characteristic (e.g., temperature, pressure or level)it causes displacement or expansion of a connecting means (e.g., fluid)within the line 122, and such displacement in turn causes movement ofthe lug 124, whereupon the lug moves upwardly as shown in FIGURE 2,thereby tilting the mercury switch, and breaking connection in a circuitin which the mercury switch is included. The described arrangement isshown schematically, and is illustrative, since various types ofcharacteristic sensing means may be used without departing from thescope and spirit of the invention. The electrical current which existsin the line 60' leading to the control box is fed directly by the line1411 to the safety control valve 48, and is fed through the mercuryswitch via line 47 to the valve 46. Since both of these valves areelectrically responsive, if the pilot should shut-off, then there is noelectrical current in the line 60, and in turn there is no power fed tothe valve 46 or to the valve 48, regardless of other connections. Thus,in the event of pilot failure, both the valve 46 and the valve 48 stopthe respective flow therethrough. However, when hte pilot is operatingunder normal conditions, the output from the generating device andelectrical current which exists in the line 60 serve to maintain thesafety valve 48 operative, or open, and through the mercury switch 110,serve to maintain the valve 46 operative. Both the valves 46 and 48, asindicated above, are of the solenoid operated type wherein the flow ofcurrent therethrough causes opening thereof, and the stoppage of currentflow thenethrough, results in closing thereof.

Before considering the overall operation of the components shown inFIGURE 2, it is desirable to understand the construction and operationof the pressure responsive activating device 42. As shown in FIGURE 5,such device comprises a hollow housing generally designated by thenumeral which is closed at the upper end 171 thereof. A piston 172 isreciprocally movable in the housing toward and away from the end 171. Apiston rod 173 which forms at least part of the mechanical coupling 58referred to above extends from the lower face of the piston, and iscoupled with the piston by a suitable threaded coupling 174. Theopposite face of the piston, the upper face, and the end 171 of thehousing 170 form opposed walls of a closed chamber 175 within thehousing. A flexible diaphragm 176 is sealingly fixed at its edges withinthe housing and extends entirely across the housing within the chamber175. The diaphragm divides the chamber 175 into two adjacent sections177 and 178. The section 177 is defined between the upper face of thepiston 172 and the lower face of the diaphragm 176. The other section178 is defined between the upper face of the diaphragm 176 and theclosed end 171 of the housing. The diaphragm, as shown, is engageablewith the upper face of the piston with flexing of the diaphragm.Moreover, the housing has an input coupling 180 to the section 178 ofthe chamber 175.

The housing 170, as shown, preferably comprises a side wall formingmember having a bore 191 extending between opposite ends thereof. Oneend of the member 190, namely the upper end as shown, has an upstandingsealing projection 192 extending continuously thereabout. The top wallof the housing is preferably formed by a separate plate 193 having thecoupling 1S6 therein. Means, preferably in the form of bolts 195 areprovided for securing the top wall plate 1% on the upstanding sealingprojection 192, and the diaphragm 176 is disposed and sealed between theupstanding sealing projection 192 and the plate member 193. Of course,with tightening of the bolts 195, sealing relationship as required isachieved.

The bottom end of the housing 170 is adapted to be coupled to a valve tobe actuated thereby, and for this purpose a bottom wall plate 200 havingan aperture 202 therein slidably receiving the piston rod 173 isprovided. This bottom wall plate may well comprise the upper plate of :avalve assembly, or a separate unit adapted to receive screws such asthose designated by the numeral 2613 for coupling the device of FIGURE 5with the valve to be activated thereby. Quite naturally, as should beapparent, when vapor under pressure enters the coupling 180, the samepresses downwardly on the diaphragm 176 thereby causing downwardmovement of the piston 172 and the piston rod 173. The downward movementof the piston rod 173 causes opening of the valve 56 (FIG- URE 2).Opening 193 permits downward movement, and automatic return of thepiston to normal position re sults from the action of valve 56 which isnormally biased closed so as to urge the piston upwardly.

In initial operation of the system of FIGURE 2, the activating button220 of the safety valve 48 is depressed, thus feeding fuel to the pilotburner system, and pilot fuel outlet thereof, and such fuel is ignited.Thereupon an electrical current is generated which serves to maintainthe valve 48 open, and which transmits through the mercury switchsuitable power to the valve 46 to maintain the same open. Initially, theflow of vapor L.P.G. through the line 20 transcends the regulator 52 andpasses through the valve 48. When the valve 46 operates, however, theL.P.G. flows through the regulator 50 primarily to the outlet coupling12'. At the same time, the pressure of the vapor L.P.G. flowing into theline 20 is transmitted through the auxiliary line 40 to the pressureresponsive activating device 42, and this causes a flexing of thediaphragm 176, and downward movement of the piston rod 173 whereupon thevalve 56 opens thereby feeding liquid L.P.G. through the line 22 to thecoupling and the main burner system. The overall control arrangement isthen in operation. As the burner system heats the body to which heat isto be transmitted, the sensing means 38 or more particularly probe 120thereof senses a predetermined characteristic (e.g., temperature) andcauses displacement within the coupling line 122 which in turn causesdisplacement of the member 124. This results in tilting of the mercuryswitch 110 and dis connection of the valve 46 from a source ofelectricity. Accordingly, the valve 46 closes thereby preventing theflow of L.P.G. vapor through the bypass portion of the line 20. At thistime, however, the vapor Within the auxiliary conduit 40 and pressuresensitive actuating device 42 is permitted to drain through theregulator 50 and to the output coupling 12. This drain results in upwardflexure of the diaphragm 176 and closure of the valve 56 whereupon thesupply of liquid L.P.G. to the output coupling 10' is stopped. When thevapor within the auxiliary line 40 has drained therefrom, or at leastthe pressure thereof has reduced to a sufficient value, then theregulator 52 opens, or opens further, permitting vapor L.P.G. to passtherethrough and to the output coupling 12. Thus, a supply of fuel tothe pilot is maintained at all times, but at the same times the vapor ispermitted to drain from the auxiliary line 40 and pressure responsivedevice 42.

Now, when the characteristic of the body to be heated again decreases,then the member 124 retracts downwardly, as shown, the mercury switchreturns to its original position under the action of the spring 128,current is again fed to the valve 46, pressure is again transmittedthrough the auxiliary line 40 to the pressure responsive activatingdevice 42, and in turn the valve 56 is again opened whereupon fuel isagain supplied to the main burner system and heat is again generated.If, however, during any operation of the system, the pilot should cutoff, then there is no power fed to the valve 46 or the safey valve 48,and both of these valves remain closed under all conditions.

Should this shutoff occur prior to drain of vapor from the auxiliaryline 40, with the arrangement of FIGURE 2, the vapor in the auxiliaryline 40 cannot escape therefrom. Thus, preferably, the valve 48 isplaced between the output ends of the regulators 50 and 52, as shown inFIGURE 1 and in any event, vapor is permitted to escape from theauxiliary line 40 and pressure responsive activating device 42.

From the preceding description, it should be apparent that the lines 22and serve respectively as first and second conduit means, the firstconduit means communicating directly solely the lower ortion of thesupply tank with the master burner arrangement, and the second conduitmeans communicating directly solely the upper portion of the tank withthe pilot burner arrangement. The valve means 56 is connected in thefirst conduit means, consistent with this description, for opening andclosing the first conduit means and thereby disestablishingcommunication between the lower portion of the tank and the masterburner arrangement. The sensing means 38 senses heat transferred by theburner arrangement to a given body, and the components within thecontrol arrangement designated by the numeral 300 in FIGURE 1 serve tooperate the valve means 56 to open and close the first conduit means inaccordance with the heat sensed by the sensing means 38. The othercomponents shown can similarly be regarded as means for performing theprescribed functions, but since the operation has been explained infull, and the means have been referred to consistent with terminologyused in the appended claims, further repetition appears unnecessary.

Conclusion After reading the foregoing detailed description of theillustrative and preferred embodiments of the instant invention, itshould be apparent that the objects set forth at the outset of thespecification have been successfully achieved. It should also beapparent that various modifications may be made in the methods andsystems provided hereby, and accordingly, what is claimed is:

1. For use with a body to be heated, apparatus for controlling thesupply of L.P.G. from an enclosed tank, having L.P.G. in a liquid stateunder pressure in the lower portion thereof and L.P.G. under pressure ina vapor state in the upper portion thereof, to a burner system having amaster burner means adapted to receive L.P.G. in a liquid state and apilot burner means adapted to receive L.P.G. in a vapor state, saidapparatus comprising the combination of:

(a) first conduit means communicating directly solely the lower portionof said tank with said master burner arrangement;

(b) second conduit means communicating directly solely the upper portionof said tank with said pilot burner arrangement; 7

(c) valve means connected in said first conduit means for opening andclosing said first conduit means and thereby disestablishingcommunication between said lower portion of said tank and said masterburner arrangement;

(d) means for sensing a characteristic of said body related to the heattransferred thereto by said burner system;

(c) control means for operating said valve means to open and close saidfirst conduit means in accordance with the heat sensed by said means forsensing, said control means being electrically powered, said controlmeans including pressure sensitive actuating means for operating saidvalve means, auxiliary conduit means communicatingly coupling saidactuating means with the second conduit means to transmit L.P.G. in saidsecond conduit means to said actuating means for operation thereof bythe pressure of L.P.G. so transmitted thereto, second valve means foropening and closing said auxiliary conduit means, and means for allowingL.P.G. to escape from said actuating means when said auxiliary conduitmeans is closed;

(f) generating means for producing an electrical current from heatcreated by said burner system;

(g) means coupling said generating means with said control means topower said control means with sai current; and

(h) means for operatively coupling said means for sensing to said secondvalve means to open and close said auxiliary conduit means in accordancewith the heat sensed by said means for sensing, and to thereby controlthe pressure applied to said actuating means by said L.P.G.

2. The combination defined in claim 1 wherein said second valve means iselectrically powered, and wherein said control means further includesmeans coupling said generating means to said second valve means to powersaid second valve means with said current.

3. The combination defined in claim 2 wherein said auxiliary conduitmeans is connected in parallel across a portion of said second conduitmeans, and wherein said combination further includes electricallyoperated safety valve means connected in said second conduit means forat least opening and closing communication between said portion of saidsecond conduit means and said pilot burner means, and means couplingsaid generating means with said safety valve means to power said safetyvalve means with said current.

4. The combination defined in claim 3 and further including firstpressure sensitive flow regulating means connested in said auxiliaryconduit means between said actuating means and said pilot means, andsecond pressure sensitive flow regulating means connected in saidportion of said second conduit means in parallel with said auxiliaryconduit means, each of said pressure sensitive flow regulating meansbeing operative to at least decrease the flow of the respective conduitmeans in which they are connected when the pressure of L.P.G. at thejunction of the auxiliary conduit means and second conduit means nearestthe pilot burner means exceeds a predetermined value, said firstpressure sensitive regulating means being operatively responsive to ahigher predetermined value than said second pressure sensitiveregulating means.

5. For use with a body to be heated, apparatus for controlling thesupply of L.P.G. from an enclosed tank, having L.P.G. in a liquid stateunder pressure in the lower portion thereof and L.P.G. under pressure ina vapor state in the upper portion thereof, to a burner system having amaster burner means adapted to receive L.P.G. in a liquid state and apilot burner means adapted to receive L.P.G. in a vapor state, saidapparatus comprising the combination of:

(a) first conduit means communicating directly solely the lower portionof said tank with said master burner arrangement;

(b) second conduit means communicating directly solely the upper portionof said tank with said pilot burner arrangement;

(c) valve means connected in said first conduit means for opening andclosing said first conduit means and thereby disestablish-i'ngcommunication between said lower portion of said tank and said masterburner arrangement;

(d) means for sensing a characteristic of said body related to the heattransferred thereto by said burner system;

(e) control means for operating said valve means to open and close saidfirst conduit means in accordance with the heat sensed by said means forsensing, said control means being electrically powered, said controlmeans including pressure sensitive actuating means for operating saidvalve means, auxiliary conduit mean-s communicatingly coupling saidactuating means with the second conduit means to transmit L.P.G. in saidsecond conduit means to said actuating means for operation thereof bythe pressure of L.P.G. so transmitted thereto, second valve means foropening and closing said auxiliary conduit means, and means for allowingL.P.G. to escape from said actuating means when said auxiliary conduitmeans is closed, said actuating means operating said valve means inaccordance with the pressure of LPG, in said second conduit means; and

(f) means for controlling said actuating means in accordance with thecharacteristic sensed by said means for sensing.

6. The combination defined in claim 5 wherein said means for controllingsaid actuating means is electrically responsive, and further includinggenerating means for producing electricity in response to heat generatedby said burner system, and means for feeding said electricity to saidcontrol means to power said control means.

7. In a burner apparatus having (a) a master burner system including amaster burner fuel outlet and vaporizing means for converting liquidfuel fed to said burner system from a liquid state to a vapor state, (b)a pilot burner system including a pilot fuel outlet ignitably associatedwith said master burner fuel outlet, and (c) an L.P.G. supply comprisingan enclosed tank containing L.P.G. under pressure in a liquid state inthe lower portion thereof and L.P.G. under pressure in a vapor state inthe upper portion thereof, the improvement comprising the combinationof:

(1) means adapted to direct L.P.G. in a vapor state solely from theupper portion of said tank to said pilot fuel outlet;

(2) means adapted to direct L.P.G. in a liquid state solely from thelower portion of said tank to said vaporizing means;

(3) means adapted to convert L.P.G. fed to said vaporizing means into avapor state within said vaporizing means;

(4) means adapted to direct said L.P.G., as converted, from saidvaporizing means to said master burner fuel outlet;

(5) means adapted to burn said L.P.G., as converted and fed to saidmaster burner outlet, adjacent said master burner outlet; and

(6) means adapted to continuously burn said L.P.G. as feed to said pilotfuel outlet while said L.P.G. is directed in a vapor state solely fromthe upper portion of said tank to said pilot fuel out-let, while saidL.P.G. in a liquid state is directed solely from the lower portion ofsaid tank to said vaporizing means, while said L.P.G. fed to saidvaporizing means is converted into a vapor state within said vaporizingmeans, while said L.P.G., as converted, is directed from said vaporizingmeans to said master burner fuel outlet, and while said L.P.G. asconverted and fed to said master burner outlet, is burnt adjacent saidmaster burner outlet.

8. The improvement defined in claim 7 and further including meansadapted to control the quantities of L.P.G. directed from said tank tosaid pilot fuel outlet and vaporizing means respectively to maintain thepressure of said L.P.G. in a vapor state within said tank and on saidL.P.G. in a liquid state with-in said tank at least substantiallyconstant during operation of the other said means.

9. The improvement defined in claim 7 and further including:

(7) a body to be heated by said apparatus;

(8) means adapted to sense when a characteristic of said body related tothe heat transferred thereto by said apparatus has reached at least onepredetermined level; and

(9) means adapted to control the feed of liquid L.P.G. to said masterburner outlet in response to sensing of said predetermined level.

10. The improvement defined in claim 7 and further including:

(7) a given body to be heated by said apparatus;

(8) means adapted to sense a given characteristic of said body at leastwithin a predetermined range having at least general upper and lowerlevels;

(9) means adapted to stop the feed of liquid L.P.G. to said masterburn-er system in response to sensing of the upper level within saidpredetermined range; and

(10) means adapted to start the feed of liquid L.P.G.

- 1 5 V p to said master burner system in response to sensing of thelower level within'said predetermined range. 1 11. .The improvementdefined in claim 9 and further including: 4 1 l (11) storage meansadapted t-o'enclose a portion of said L.P.G. in a v'aporstate separatefrom but communicatin g with said upper portion of said tank whereby theenclosed portion of said LIP.G. normally has 'a pressure at leastproportional to the pressure of said L.P.G. in .a vapor state withinsaid tank; (12 means communicating said storage tr'neans with said meansadapted to start and said means adapted to stop whereby said meansadapted to start and said means adapted -to stop are responsive to thepressure of said L.P.G. in said storage means; (13) meansladapted tosubstantially reduce the pressure of said L.P.G; in said storage meansin response p to sensing of said upper level within said predeterminedrange by closing communication between'sa'id tank and said storage meansand permitting L.P.G. in said storage means to pass therefrom; and (14)means adapted "to substantially increase the pressure of said L.P.G. insaid storage means in response to sensing of'said lower level withinsaid predetermined range by opening communication between said tank andsaid storage means. 12; The improvement defined in claim 11 and furtherincluding: r

(15 means adapted to direct L.P.G. passing from said storage means tosaid pilot fuel outlet. 13. The improvement defined in claim 12 andfurther including: i 5 (16) means adapted to control the feed of L.P.G.from said upper portion of said tank to said pilot fuel outletan-d'control the feed of L.P.G. permitted to pass from said storagemeans to said pilot fuel outlet to provide a continuous substantiallyuniform feed of L.P.G. to said pilot fuel outlet and continuous 1Q iburning thereof.

References Cited by the Examiner UNITED STATES PATENTS 1,508,792 9/1924Hornung 15s 2s 1,995,846 3/1935 Gauger 231- 21 2,070,209 2/1937 Kerr,15s s1 X 2,700,987 2/1955 Whalen 92- 101 2,724,410 11/1955 Vorech92-101 20 2,767,355 10/1956 Wolff 236-21 X 2,781,977 2/1957 Stanley 61a1 236 21 2,839,130 6/1958 St. Clair 158-28 FREDERICK L. MATTESON, 111.,Primary Examiner.

1. FOR USE WITH A BODY TO BE HEATED, APPARATUS FOR CONTROLLING THESUPPLY OF L.P.G. FROM AN ENCLOSED TANK, HAVING L.P.G. IN A LIQUID STATEUNDER PRESSURE IN THE LOWER PORTION THEREOF AND L.P.G. UNDER PRESSURE INA VAPOR STATE IN THE UPPER PORTION THEREOF, TO A BURNER SYSTEM HAVING AMASTER BURNER MEANS ADAPTED TO RECEIVE L.P.G. IN A LIQUID STATE AND APILOT BURNER MEANS ADAPTED TO RECEIVE L.P.G. IN A VAPOR STATE, SAIDAPPARTUS COMPRISING THE COMBINATION OF: (A) FIRST CONDUIT MEANSCOMMUNICATING DIRECTLY SOLELY THE LOWER PORTION OF SAID TANK WITH SAIDMASTER BURNER ARRANGEMENT; (B) SECOND CONDUIT MEANS COMMUNICATINGDIRECTLY SOLELY THE UPPER PORTION OF SAID TANK WITH SAID PILOT BURNERARRANGEMENT; (C) VALVE MEANS CONNECTED IN SAID FIRST CONDUIT MEANS FOROPENING AND CLOSING SAID FIRST CONDUIT MEANS AND THEREBY DISESTABLISHINGCOMMUNICATION BETWEEN SAID LOWER PORTION OF SAID TANK AND SAID MASTERBURNER ARRANGEMENT; (D) MEANS FOR SENSING A CHARACTERISTIC OF SAID BODYRELATED TO THE HEAT RRANFERRED THERETO BY SAID BURNER SYSTEM; (E)CONTROL MEANS FOR OPERATING SAID VALVE MEANS TO OPEN AND CLOSE SAIDFIRST CONDUIT MEANS IN ACCORD-